The present invention relates to a method and device for anchoring struts of articles standing on the ground such as a stockade, ground mark or guardrail to the ground.
As is well known in the art, various attempts have heretofore been made to effect anchoring of the struts to the ground. Typical one of these prior expedients is to dig the ground to a predetermined depth and thereafter inserting a lower portion of the strut provided with a crossing anchoring pin whereupon small rocks and sand are rammed into the bore. Another prior expedient is to bury a concrete-block formed with a bore into which the strut is inserted and supported thereby.
In the prior art expedients, it is necessarily required to dig the ground to a depth of about 60 cm to form a bore for accomodating the strut. This step is usually performed by hands which are inefficient and need many hours. Another drawback encountered with the former expedient resides in the fact that the small rocks and sand are required in a larger amount resulting in the increase in the cost for completing the anchoring of the strut to the ground. A drawback is also encountered in the latter expedient in that a relatively larger bore should be formed in order to accomodate the concrete-block and, since a relatively larger gap exists between the periphery of the concrete-block and the bore, it is necessary to fill up the gap to fixedly support the concrete-block in the ground. This is reflected by difficulty in manipulation of the concrete-block having the larger weight and the increase in the carriage so that the final cost for performing anchoring of the strut is considerably increased.
In order to overcome these drawbacks encountered in the prior art expedients, it has heretofore been proposed to provide a supporting pipe formed with a bore having a diameter to tightly accomodate the strut and provided at its outer periphery with various supporting means. The supporting pipe is normally driven into the ground by some driving means and, thereafter, the strut is tightly fitted into the bore formed in the pipe. This expedient is, however, disadvantageous in that it is difficult to drive the pipe into the ground at a given angle due to obstacles such as small rocks contained in the ground and the pipe is finally driven into the ground in a displaced condition. If the supporting pipe is inserted into the bore of the ground in the displaced condition, the struts supported by the pipes displaced in the ground can not be aligned with each other and become impractical.